Mark Krikorian has stated that out of the 48 al-Qaeda operatives who committed crimes in the US between 1993 and 2001, 12 of them were illegal immigrants when they committed their crimes and seven of them were visa overstayers (including two of the conspirators in the first World Trade Center attack, one of the figures from the New York subway bomb plot, and four of the 9/11 terrorists).

Vice Chair Lee H. Hamilton and Commissioner Slade Gorton of the National Commission on Terrorist Attacks Upon the United States commented that of the nineteen hijackers in the September 11, 2001 attacks,

Two hijackers could have been denied admission at the port on entry based on violations of immigration rules governing terms of admission. Three hijackers violated the immigration laws after entry, one by failing to enroll in school as declared, and two by overstays of their terms of admission.

Since the attacks of September 11, 2001, illegal immigrants within the United States have attempted to carry out other terrorist attacks as well.

Three of the six conspirators in the 2007 Fort Dix attack plot—Dritan Duka, Shain Duka, and Eljvir Duka—were ethnic Albanians from the Republic of Macedonia who entered the United States illegally through Mexico with their parents in 1984.

Hosam Maher Husein Smadi, an illegal immigrant from Jordan who remained in the United States after the expiration of his tourist visa, was arrested in September 2009 for attempting to carry out a car bomb attack against Fountain Place in Dallas.

In the case of Rasmea Odeh, she was convicted of immigration fraud in 2014 for concealing her arrest, conviction, and imprisonment for a fatal terrorist bombing in Israel.

Such anecdotal evidence, while not statistically significant, is important to consider.

Unlike the American founding fathers, who were classical liberals, those who helped bring together the Commonwealth of Australia were social liberals.

From the very beginning of Australian history, utilitarianism was the dominant philosophy. Economic liberty, while seen as important, was never viewed as an inviolable freedom derived from natural law. Rather, private property could be abrogated whenever the “national interest” – as defined by the government – demanded it.

Yet despite its Bill of Rights and widespread ideological resistance to Big Government, the American experiment has reached approximately the same position as Australia. Both America and Australia are now social democracies with large welfare states. In America, there is also a gigantic warfare state. A country founded on libertarian principles has reached the same place as one founded on utilitarianism and expediency. What conclusion are we to draw from this state of affairs?

The most obvious would seem to be that limited government doesn’t work. The State always has a tendency to grow in size and scope.

A piece of paper known as ‘the Constitution’ cannot halt the growth of government. The American constitution is a relatively libertarian document. Yet it has proved ineffective in preventing the concentration of power.​I think it is clear, therefore, that constitutions are not what keeps government in its place. Only ideology and a commitment to liberty amongst the people can prevent government from growing, not pieces of paper that have been largely ignored by the judiciary anyway.

I find it hard to think of any innovation in taxation - any new form of taxation, any new way of collecting taxes - that was not brought into being as part of a government scheme to pay for war.

– Robert Higgs, “Death Fuel”, 2009What has caused the growth of government in the 20th century?

Historical analysis can provide the answer to this question. In particular, it is essential to study the history of warfare. The State grows during times of war -- to the detriment of individual liberty. As Randolph Bourne famously said, ‘War is the health of the State’.

In Australia, it was the World Wars that set the fiscal, institutional and ideological precedents that allowed for the rise of big government. The wars legitimated Keynesianism by allowing social democrats to speak lovingly of the wonders of central direction of the economy.​World War I, in which nearly 60,000 Australians died, saw moves towards centralization of political power over the individual. As Neil Barnwell points out, the nationalist sentiment brought about by the “Great War” has been adeptly harnessed by governments ever since:

Large scale government involvement in [World War I] paved the way for further government involvement in the economy, culminating in the period of extensive public ownership and regulation of industry after 1945. Government industrial and organisational initiatives in marshalling and managing resources for the war effort helped erode argument that markets and private ownership were the best promoters of economic development. Additionally, the repatriation of returned soldiers led to government involvement in social programs on a scale never before anticipated or expected. Thus the First World War paved the way for an expanded role of government in industry and society once the war was over.

The Second World War left similar legacies. As the authors of The Oxford Companion to World War II observe (p. 82):

War traditionally gives governments increased powers. For Australia the Second World War shifted the balance of power away from the states and in favour of the federal government, with the permanent move of the powers of taxation to the centre. Moreover, the federal government’s increased controls over goods and services, including manufacturing and transport, gave it confidence to experiment with a planned mixed economy.

Judicial interpretations during Australia’s major wars send a clear message. The cases have favoured centralisation over federalism, and have tended to grant government virtually unlimited scope. Courts have upheld a military draft – arguably unconstitutionally - as well as a variety of regulations very indirectly linked to defence. Wage and price controls, food rationing, the detention of Japanese Australians; these and many other interventions rode roughshod over liberty.

Those who favour free-markets should re-think their attitude towards war in light of the above.